If you were to pick the worst possible place for an oil spill in the Great Lakes, this would be it

— David Schwab, Ph.D., research scientist at the University of Michigan Water Center

What is Line 5? Why is it a threat?

Two oil and gas pipelines, known collectively as Line 5, run under the straits of Mackinac - the waterway connecting Lake Michigan and Lake Huron.

This 64 year old pipeline, owned by Enbridge, was projected to last 50 years. Current environmental laws would not permit it to be constructed today due to the risk posed to the Great Lakes. Yet every day, nearly 23 million gallons of oil flow through the 5 miles of pipeline just west of the Mackinac Bridge.